CRATER SERVICE TRIP — The Friends of Haleakala National Park is sponsoring a two-night service trip Thursday-Saturday to remove telegraph plants at the crater's Kapalaoa Cabin. Call (808) 248-7660.

MAUI FOREST RESTORATION — The Maui Dryland Forest Restoration Group's next workday is 8 a.m.-4 p.m. July 21. Volunteers and four-wheel-drive vehicles needed. Meet at 'Ulupalakua Ranch Store. Hiking boots that cover the ankles are required; clean all gear and boots of dirt that may carry seeds. Bring rain gear, water, lunch, sunscreen, hat. Register by July 19 at auwahi @yahoo.com or (808) 572-4471.

MAKIKI WAI HELPERS — The state Department of Land and Natural Resources and Hawai'i Nature Center need volunteers on July 23 to make trail improvements, remove weeds and plant native plants along a Makiki trail as part of the Makiki watershed awareness initiative. Water, gloves and tools provided; bring long pants and long-sleeve shirt, shoes or boots, insect repellent and lunch. Meet at the Makiki Forestry Baseyard at 9 a.m. Call 973-9782, or see www.hawaiitrails.org/trail.asp?TrailID =OA+19+004&island=Oahu.

HALEAKALA VOLUNTEERS — The next Laulima o Haleakala drop-in workday is 9 a.m.-noon Saturday. Projects include non-native species removal, weeding of planters and trash pickup. Appropriate for age 6 and up. Meet at summit maintenance yard at 9 a.m.; wear long pants and closed-toe shoes, and bring rain gear, sunscreen, hat, layered clothing, water and lunch. Reservations required for groups of six or more. Contact the Haleakala Volunteer Program office at HALE_VIP_Coordinator@nps.gov or (808) 572-4487.

WINDWARD WORKDAY — The Windward Ahupua'a Alliance and 'Ahahui Malama I Ka Lokahi are sponsoring the Great Kapa'a Valley & Kawai Nui Marsh Community Stewardship Workday, 8:30-11:45 a.m. July 30. Volunteers ages 11 and up are needed to help with check-in, operate a hospitality tent, pick up litter on the quarry road, clear the marsh view plane, plant native plants, and drive trucks to pick up bagged trash. Wear close-toed shoes with gripping soles, long-sleeved shirts, insect repellent, sunscreen, and a hat; breakfast, lunch, water and snacks provided, along with gloves and trash bags. Advance registration required: 247-6366, 223-5535, or info@waa-hawaii.org.

MANOA FALLS TRAIL WORK — The Sierra Club needs volunteers to move 100 tons of gravel onto the Manoa Falls Trail. Saturday workdays are Aug. 6 and 21, Sept. 3 and 18, Oct. 1 and 23. Meet at 8 a.m. at Church of the Crossroads, 2510 Bingham St., to car pool. Work ends by 2 p.m., and refreshments follow. Contact Randy Ching at 942-0145 or oahurandy@yahoo.com.

KANE'OHE WETLAND PROJECT — Volunteers are needed Aug. 13 to help the Sierra Club clear a wetland of mangrove to create habitat for endangered water birds at Marine Corps Base Hawai'i. Because the base is a secured military facility, volunteers must provide name and Social Security number in advance and bring a signed waiver. Call Annette Kaohelauli'i at 235-5431.

MORNING TRAIL SWEEPERS — Lyon Arboretum in Manoa seeks early morning walkers to hike the arboretum trails, clearing debris. Call volunteer coordinator Donna Schult at 988-0464. The arboretum also has volunteer work-party days on the first, third and fourth Saturdays of each month.

WEED & POT CLUB — The Maui Nui Botanical Garden's Weed & Pot Club meets 8:30-10:30 a.m. Wednesdays at 150 Kanaloa Ave. in Kahului to work on nursery plants and perform beautification and maintenance work. Tools, gloves and drinking water provided; bring sunscreen; wear shoes.

For a free listing, write to For the Environment, P.O. Box 156, Wailuku, HI 96793; cwilson@honoluluadvertiser.com; or fax (808) 242-1520.